Dry powder inhaler and inhalation actuated mechanism thereof

ABSTRACT

A flap (20) for an inhalation actuated mechanism (18) of a powder inhaler (1) comprises a base member (29), a skirt structure (24) projecting from a surface of the base member (29), and a coupling portion (21) to be coupled to a resilient member (40′) of the inhalation actuated mechanism (18).

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of copending application U.S. Ser.No. 14/755,658, filed on Jun. 30, 2015, which claims under 35 U.S.C. §119(a) the benefit of European Application No. 14 175 021.6, filed Jun.30, 2014, the entire contents of which are incorporated by referenceherein.

BACKGROUND (a) Technical Field

The present invention relates to a flap for an inhalation actuatedmechanism of a powder inhaler and a corresponding powder inhaler.

(b) Description of Related Art

Powder inhalers are devices for dispensing a powdered medicamentpreparation by inhalation. The administering of a powdered medicamentpreparation by inhalation from an inhaler is commonly known.

EP 1 386 630 B1 by the applicant of this patent application discloses aportable multiple-dose device without propellant gas, which is equippedwith a metering member for dispensing doses from a medicament container.The device is based on a centripetal force for achieving a moreeffective pulverization/deagglomeration of the particles of themicronized powdered medicament from a coarser carrier in such a mannerthat the penetration of the medicament into the lungs of a user orpatient is improved and the adhesion of the powdered medicament to theupper respiratory passages is reduced for alleviating possible sideeffects caused thereby. The device of EP 1 386 630 B1 comprises aprotective member, preferably a thin plate sliding on the meteringmember, the protective member being moveable between a closed position,in which it at least covers a dosing recess of the metering member toprevent the powdered medicament contained in the dosing recess fromentering into an inhalation channel of the powder inhaler, and an openposition, in which the protective member does not cover the dosingrecess, so that the dosing recess is exposed to the inhalation channelto enable inhalation of the dose of the powdered medicament contained inthe dosing recess. The protective member prevents a metered dose of thepowdered medicament from falling out of the dosing recess, therebypreventing an unintentional loss of the powdered medicament.

The protective member is preferably automatically withdrawn and movedfrom its closed position into its open position upon an inhalationprocess. Thus, the powder inhaler can be used in a variety oforientations, even upside down when the user or patient is lying in abed, for example.

In order to automatically withdraw the protective member from its closedposition and move it into its open position, the powder inhaler of EP 1386 630 B1 comprises an inhalation actuated mechanism which is designedand coupled to the protective member such that it moves the protectivemember into its open position if the inhalation suction force of therespective user exceeds a predetermined value. The inhalation actuationmechanism is further constructed such that it automatically returns theprotective member into its closed position after the respectiveinhalation process has properly been completed.

The present invention especially relates to a further development ofthis inhalation actuated mechanism, so that in the following theinhalation actuated mechanism known from EP 1 386 630 B1 will bedescribed in more detail. As the further configuration of the powderinhaler of the present invention may be similar or even identical to thepowder inhaler known from EP 1 386 630 B1, the disclosure of EP 1 386630 B1 is hereby incorporated by reference in its entirety.

FIG. 4 shows a cross-sectional view of the powder inhaler known from EP1 386 630 B1.

As shown in FIG. 4, the powder inhaler comprises a casing with a lowershell 1 and an integral cover 2 being pivotably or rotatably coupled tothe lower shell 1. The integral cover 2 can be opened to reveal amouthpiece 3 with which a user can inhale a powdered medicament. Thepowder inhaler comprises a dosing sub-assembly comprising a container orreservoir 4 for storing the powdered medicament, the metering member 5,and a deagglomerator arrangement 10 to be coupled to the inhalationchannel 9 of the mouthpiece 3. The deagglomerator arrangement 10 isconstructed such that it generates a cyclonic airflow resulting in astrong velocity gradient.

The metering member 5 is preferably provided in the form of a shuttle orslide which is moveable in the horizontal direction and has the dosingrecess 15 in the form of a dosing cup formed in a longitudinal middleregion thereof. The dosing recess 15 is provided for metering a dose ofthe powdered medicament and for transporting the dose from a fillingposition underneath the container 4, in which the dosing recess 15 is inalignment with an opening at the bottom of the container 4, to aninhalation position underneath the deagglomerator arrangement 10, inwhich the dosing recess 15 is in alignment with the inhalation channel9.

The powdered medicament is stored in a medicament chamber of thecontainer 4. Furthermore, the container 4 may comprise a desiccantchamber storing a desiccant for absorbing moisture that may have enteredthe medicament chamber. As indicated in FIG. 4, the desiccant chambermay be separated from the medicament chamber by a permeable membrane.The medicament chamber has a gradually decreasing cross-section diameterfrom its top to its bottom so that the medicament chamber of thecontainer 4 is shaped like a funnel supporting an easier filling of thedosing recess 15.

The metering member 5 is coupled to the cover 2 by a coupling mechanism,e.g., a coupling mechanism comprising profiled cam tracks, which isconstructed such that opening the cover 2 causes the metering member 5to move forward from its filling position to its inhalation position.Likewise, closing of the cover 2 causes the metering member 5 to movefrom its inhalation position backward to its filling position.

As already indicated above, during the movement of the metering member 5from the filling position to the inhalation position as well as afterthe metering member 5 has reached its inhalation position, the dose ofthe powdered medicament filled in the dosing recess 15 is prevented fromfalling out by the protective member 7. The protective member 7 isslidable on the metering member 5 between its closed position, in whichis covers the dosing recess 15, and its open position, in which itexposes the dosing recess 15 to the deagglomerator arrangement 10 andthe inhalation channel 9 when the metering member 5 is in the inhalationposition. The protective member 7 is held in its closed position by theabove-mentioned inhalation or breath actuated mechanism which isconstructed such that the protective member 7 is moved from its closedposition to its open position only if the inhalation suction forceeffected by the user in the inhalation channel 9 exceeds a predeterminedlevel. Furthermore, the inhalation actuated mechanism is constructedsuch that only an inhalation suction breath, and not a blowing breath,can actuate the mechanism and can cause a movement of the protectivemember from its closed position to its open position.

FIG. 5 shows a more detailed perspective view of the inhalation actuatedmechanism 18.

The inhalation actuated mechanism 18 comprises a sub-frame 8 which isshown in FIG. 4 only and holds a flap 20 acting as an inhalationactuated member, a coupling member 30, preferably in the form of a yoke,and a resilient member 40, preferably in the form of a drive spring. Theresilient member 40 and the coupling member 30 are provided to drive theprotective member 7 and to actuate a dose counting unit which comprisesaccording to FIG. 5 a units wheel 12 having drive teeth 16 and a tenswheel 13 having drive teeth 17, which are coupled by an idler wheel (notshown). The units wheel 12 and the tens wheel 13 display the number ofdoses remaining in the container 4.

As shown in FIG. 5, recesses 11 are formed at the front corner portionsof the metering member 5, and at one of these recesses 11 a prolongedend 43 of the resilient member 40 engages with the metering member 5 ifthe metering member is moved forward. By the contact with the meteringmember 5, the resilient member 40 is tensioned and charged up. A firstend 41 of the resilient member 40 rests at a portion 21 of the flap 20when the resilient member 40 is in its discharged state and normallyholds the flap 20 in a first position, i.e., in a horizontal position.Therefore, by charging up the resilient member 40 by opening the cover2, the reset force exerted by the first end 41 on the flap 20 isreleased.

In exemplary FIGS. 4 and 5, the upper surface of the flap 20 has anoptional flag 22 which acts as a mark that is visible through openingsin the upper side of the mouthpiece region of the powder inhaler andindicates that a dose is ready for inhalation. Furthermore, the flap 20is coupled to the coupling member 30 via an arm portion 34 thereof andcomprises one or two projections 23 acting as a counterweight. Thiscounterweight balances the flap 20 and does not only reduce theactuation force required but also the susceptibility of the mechanism toaccidental triggering.

As shown in FIG. 5, the resilient member 40 has a second end 42 whichrests on a lateral side surface of the coupling member 30. The resilientmember 40 is mounted on a shaft-like portion of the coupling member 30.At the opposite side thereof, the coupling member 30 has a projection 31with a thickening 32 for operating the dose counting mechanism. From thebottom of the coupling member 30, there extends a prolongation 33 whichengages with an opening 14 formed in the protective member 7 and with aslit (not shown in figures, as covered by the protective member 7)formed in the front end portion of the metering member 5.

When the flap 20 is held by the resilient member 40 in the horizontalposition shown in FIG. 5, the protective member 7 prevents the powderedmedicament contained in the dosing recess 15 from being displaced fromthe deagglomerator arrangement 10 if the user blows into the mouthpiece3. Furthermore, the flap 20 provides a resistance if the user blows intothe device giving positive feedback. If, however, the metering member 5is pushed forward by opening the cover 2, the resilient member 40 iscompressed and charged, and the reset force exerted by the end 41 on theflap 20 is released, so that the flap 20 can pivot or rotate from thehorizontal first position into a second position that is pivoteddownward relative to the horizontal first position if there is asufficient high inhalation suction force in the inhalation channel 9. Inthe latter case, the movement of the flap 20 into its second positionreleases the arm 34 of the coupling member, which enables the resilientmember 40, due to its compression, to move its second end 42 and thusthe coupling member 30 slightly upward. By this rotational upwardmovement of the coupling member 30 the prolongation 33 extending fromthe lower side of the coupling member 30 moves forward, thereby movingthe protective member 7 from its closed position to its open positionand exposing the dosing recess 15 to the inside of the deagglomeratorarrangement (cyclone) 10, so that the dose of the powdered medicamentcan be inhaled through the deagglomerator arrangement 10 and theinhalation channel 9 as well as the mouthpiece 3. In the cyclone ordeagglomerator arrangement, the powdered medicament is entrained into aswirling airflow where the active part of the formulation isdisaggregated from the carrier.

In exemplary FIGS. 4 and 5, since the flap 20 has been moved to itssecond position, the optional flag 22 will no longer be visible throughthe corresponding opening in the upper side of the mouthpiece, therebyindicating that a dose has been taken and that a new dose is not yetready for inhalation.

Furthermore, as a result of this rotation of the flap 20 and thefollowing clockwise rotation of the coupling member 30, the projectionor cantilever 31 of the coupling member 30 is also slightly movedclockwise along the inclination of a next drive tooth 16 of the unitswheel 12 so as to bring the thickening 32 into engagement with therespective drive tooth 16.

After inhalation, when the user closes the cover 2 again, the meteringmember 5 is moved backward to the filling position underneath thecontainer 4, and this backward movement causes a counterclockwiserotation of the coupling member 30 as the prolongation 33 thereof ismoved backward with the metering member 15. The counterclockwiserotation of the coupling member 30 is supported by the resilient member40 which is allowed to be discharged and decompressed upon backwardmovement of the metering member 5. Due to this counterclockwise rotationof the coupling member 30, the projection 31 is also rotatedcounterclockwise, thereby rotating the units wheel 12 counterclockwiseby one step which decreases the displayed number of doses left in thecontainer 4.

Since the coupling member 30 and the resilient member 40 are moved backinto their initial positions, the first end 41 of the resilient member40 urges the flap 20 back into the horizontal position shown in FIG. 4and FIG. 5. Moreover, the coupling member 30 is then again held by theengagement of its arm 34 with the flap 20, so that the whole powderinhaler has then been transferred into its initial position again.

SUMMARY

Starting from this structure and functionality of the inhalationactuated mechanism described above, it is the object of the presentinvention to provide a new flap design that allows to reduce theinhalation force required for activating the inhalation actuatedmechanism and thus contributes to an improved performance of thecorresponding powder inhaler.

According to the present invention, this object is achieved by a flapfor an inhalation actuated mechanism of a powder inhaler as defined inclaim 1 and a corresponding powder inhaler as defined in claim 15. Thedependent claims define preferred and/or advantageous embodiments of theinvention.

The flap of the invention comprises a base member, a skirt structureprojecting from a surface of the base member, and a coupling portion tobe coupled to a resilient member of a corresponding inhalation actuatedmechanism of a corresponding powder inhaler.

The new flap design with the skirt structure or frame structure formedat the upper surface of the base member has an improved interaction withthe powder inhaler chassis and an improved sealing of the casework andthe flap to internal airflows, thereby allowing an improved deviceperformance. Due to the new flap design, the inhalation flow raterequired for the activation of the breath actuated mechanism of theinhaler can be reduced, and an improved inter- and intra-devicereproducibility for the through life of the powder inhaler can beachieved, resulting also in an overall increase in the robustness of thepowder inhaler while ensuring manufacturing capability. For example,with the new flap design, the mean breath actuated mechanism activationflow rate (BAM-AFR) can be reduced to a value in the range of 25 l/min,while the previous flap design required a mean BAM-AFR in the range of38 l/min. The new flap design allows to achieve a very low variabilityof the activation flow rates for the through life of the powder inhaler,which may be in the range of 20 to 32 l/min. Thus, the inhalationactuated mechanism of the invention can be activated already at very lowinspiratory flows which can be exerted more easily by patients that areaffected by obstructive pulmonary airway diseases, such as asthma andCOPD, for example. The addition of the skirt creates a labyrinth betweenthe mouthpiece of the powder inhaler and the flap, which provides anincreased resistance to air. This increased resistance makes the triggerflow more repeatable and reproducible without the inclusion of thislabyrinth seal about the cover of the powder inhaler causing an increasein torque required to open and close the cover.

According to the preferred embodiment, the base member of the flapcomprises a flat portion from which the skirt projects and a front endof the flat portion is at least partly rounded.

The flat portion may have a first longitudinal side and a secondlongitudinal side, the first and second longitudinal sides beingconnected by a combination of a straight front end portion and a roundedfront end portion. A length of the first longitudinal side may beshorter than a length of the second longitudinal side.

According to an embodiment of the invention, the skirt comprises firstside wall portions, which substantially extend in a longitudinaldirection of the base member, and a second side wall portion whichextends between the first side wall portions in a width direction of thebase member and may comprise an elongate thickening in a middle portionthereof.

The first side wall portions are spaced from one another in the widthdirection of the base member and are preferably wedge-shaped such that aheight of the first side wall portions gradually increases from a frontend of the base member towards a rear end of the base member. Thetransverse second side wall portion may be inclined towards a rear endof the base member.

The coupling portion, interacting with the resilient member, preferablyin the form of a spring, of the inhalation actuated mechanism may extendfrom a surface of the base member which is opposite to the surface fromwhich the skirt projects.

According to an embodiment of the invention, the flap comprises awing-shaped projection that projects from the flap backwards and isdesigned such that it acts as a counterweight upon a rotation of theflap in the inhalation actuated mechanism.

In the preferred embodiment, the flap comprises a portion to be coupledto a coupling member, preferably in the form of a yoke, of theinhalation actuated mechanism, the coupling member being provided forcoupling the inhalation actuated mechanism with a protective member of ametering member of the powder inhaler. This coupling member may also beprovided for actuating a dose counting mechanism of the powder inhaler.

The flap of the present invention may preferably be used in aninhalation actuated mechanism of the type disclosed in EP 1 386 630 B1.The further configuration of the corresponding powder inhaler of thepresent invention and the functionality of the corresponding componentsmay be similar or even identical to the powder inhaler known from EP 1386 630 B1.

In the following, a preferred embodiment of the invention will bedescribed with reference to the drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C show several perspective views of inhalation actuatedmechanisms using a flap according to embodiments of the invention. Inparticular, FIG. 1A shows a perspective view of an inhalation actuatedmechanism using a flap according to an embodiment of the inventionbefore having been actuated by inhalation, FIG. 1B shows a perspectiveview of the inhalation actuated mechanism of FIG. 1A after it has beenactuated by inhalation, and FIG. 1C shows a perspective view from adifferent side of an alternative embodiment of an inhalation actuatedmechanism after inhalation has occurred.

FIG. 2 shows an enlarged perspective view of the flap shown in FIGS.1A-1C.

FIGS. 3A-3G shows several views of the flap. In particular, FIG. 3Ashows a first perspective side view of the flap similar to FIG. 2, FIG.3B shows a second perspective side view of the flap, FIG. 3C shows a topview of the flap, FIG. 3D shows a first side view of the flap, FIG. 3Eshows a second side view of the flap, FIG. 3F shows a bottom view of theflap, and FIG. 3G shows a rear view of the flap.

FIG. 4 (PRIOR ART) shows a cross-sectional view of a conventional powderinhaler in which the flap and the inhalation actuated mechanism of FIGS.1-3 may be used.

FIG. 5 (PRIOR ART) shows a perspective view of the inhalation actuatedmechanism of the conventional powder inhaler of FIG. 4.

DESCRIPTION OF SPECIFIC EMBODIMENTS

FIG. 1A shows an inhalation actuated mechanism 18 comprising a flap 20acting as an inhalation actuated member, a coupling member 30 in theform of a yoke, and a resilient member 40′ in the form of a drive springattached to a shaft portion of the coupling member 30. The resilientmember 40′ has a similar function as the resilient member 40 shown inFIG. 5, but is different from the resilient member 40 in its shape.Therefore, as regards the functionality of the resilient member 40′, ingeneral reference can be made to the above explanations regarding theresilient member 40 shown in FIG. 5. The resilient member 40′ and thecoupling member 30 are provided to drive a protective member 7 for adosing recess 15 of a metering member 5 of a corresponding powderinhaler and to actuate a dose counting unit which comprises according toFIG. 1A a units wheel 12 and a tens wheel 13. The units wheel 12 and thetens wheel 13 display the number of doses remaining in a medicamentcontainer of the powder inhaler or the number of doses that have alreadybeen taken. Drive teeth 16 of the units wheel 12 are coupled through agear mechanism (not shown) with drive teeth 17 of the tens wheel 13.According to this particular embodiment, as shown in FIG. 1A, the firstresilient member 40′ engages with its prolonged end 43 with a recess ofthe metering member 5 and rests with its end 41 at a coupling portion 21of the flap 20.

FIG. 2 shows an enlarged perspective view of the flap 20, and FIGS.3A-3G show different further views of the flap 20.

According to the embodiment depicted in FIGS. 2 and 3A-3G, the flap 20comprises a base member 29 with a substantially plate-shaped flatportion 60 from which a skirt or frame structure 24 projects upward. Theskirt extends along the circumference of the base portion 29, but isopen toward the front. The coupling portion 21 to be coupled to theresilient member 40′ of the inhalation actuated mechanism 18 projectsfrom the lower surface of the base portion 29 downward. Furthermore, thebase member 29 comprises a shaft portion 28 at a rear end of the flatportion 60, the shaft portion 28 being provided to pivotably orrotatably support the flap 20 in the inhalation actuated mechanism 18within the casing of the corresponding powder inhaler.

The front end 61 of the flat portion 60 of the base member 29 is atleast partly rounded. According to the preferred embodiment, the flatportion 60 has a first longitudinal side 62 and a second longitudinalside 63, the first and second longitudinal sides 62, 63 being connectedby a combination of a straight front end portion 64 and a rounded frontend portion 65, and the length of the first straight longitudinal side62 of the base member 29 is somewhat shorter than the length of thesecond straight longitudinal side 63, which can be best seen in the topand bottom views of FIG. 3C and FIG. 3F.

The skirt structure 24 comprises first side wall portions 26B, whichsubstantially extend in a longitudinal direction of the base member 29,and a second side wall portion 26A which extends between the first sidewall portions 26B in a width direction of the base member 29. The secondside wall portion 26A comprises an integrated elongate thickening 27extending from the base member 29 upward in a middle portion of thesecond side wall portion 26A.

In the preferred embodiments shown in FIGS. 1-3, the two first side wallportions 26B are spaced from one another in the width direction of thebase member 29 and are wedge-shaped such that a height of the first sidewall portions 26B gradually increases from a front end of the basemember 29 towards a rear end of the base member 29. The second side wallportion 26A is slightly inclined towards the rear end of the base member29 (see FIG. 3C, for example).

The first side wall portions 26B extend along the first and secondlongitudinal sides of the flat portion of the base member 29. That firstside wall portion 26B, which extends along the first longitudinal sideof the flat portion of the base member 29, i.e., the left side wallportion 26B, is angled such that a part thereof extends substantiallyparallel to the straight front end portion of the base member 29. Theother first side wall portion 26B, i.e., the right side wall portion inFIG. 2, extends completely along a straight line.

As already described above, the preferably plate-shaped coupling portion21 of the inhalation actuated mechanism 18 extends from a surface of thebase member 29 which is opposite to the surface from which the skirt 24projects. A further projection 23 projects from the shaft portion 28 ofthe flap 20 backward and is wing-shaped and designed such that it actsas a counterweight upon rotation of the flap 20 in the inhalationactuated mechanism 18. The projection 23 and the coupling portion 21 arespaced in a width direction of the flap 20 and extend substantiallyparallel to one another, which can be seen best in FIG. 3G.

The flap 20 also comprises a portion 25 to be coupled to the couplingmember 30 of the inhalation actuated mechanism 18 (see FIG. 3F).

The inhalation actuated mechanism 18 comprising the flap 20 may be usedin a powder inhaler similar to that shown in FIG. 4, so that referencecan be made to the above description with respect to the structure andfunctionality of the powder inhaler. In particular, the functionality ofthe inhalation actuated mechanism 18 is similar to that described inconnection with FIG. 5.

As shown in FIG. 1A, an end 43 of the resilient member 40′ engages witha front corner portion of the metering member 5 as the metering memberis moved forward. By the contact with the metering member 5, theresilient member 40′ is tensioned and charged up. A further end 41 ofthe resilient member 40′ is coupled to the coupling portion 21 of theflap 20 such that, when the resilient member 40′ is in its dischargedstate, the flap 20 is held in a first horizontal position. Therefore, bycharging up the resilient member 40′, this reset force exerted by theend 41 on the flap 20 is released.

Furthermore, the flap 20 is coupled at its lower surface at the portion25 (see FIG. 3F) to a projection 34 of the coupling member 30 andcomprises the wing-shaped further projection 23 which acts as acounterweight and projects backward from the shaft portion 28 of theflap 20. This counterweight balances the flap 20 and does not onlyreduce the actuation force required but also the susceptibility of themechanism to accidental triggering.

As shown in FIG. 1A, the resilient member 40′ is mounted on a shaft-likeportion of the coupling member 30. At the opposite side thereof, thecoupling member 30 has a projection 31 with a thickening 32 foroperating the dose counting mechanism. From the bottom of the couplingmember 30, there extends a prolongation 33 which engages with an opening14 formed in the protective member 7 and with a slit (not shown) formedin the front end portion of the metering member 5.

When the flap 20 is held by the resilient member 40′ in the horizontalposition shown in FIG. 1A, the protective member 7 prevents the powderedmedicament contained in the dosing recess 15 from being displaced fromthe deagglomerator arrangement of the powder inhaler if the user blowsinto the mouthpiece of the powder inhaler. Furthermore, the flap 20provides a resistance if the user blows into the device giving positivefeedback. If, however, the metering member 5 is pushed forward byopening the cover of the powder inhaler, the resilient member 40′ iscompressed and charged, and the reset force exerted by the end 41 on theflap 20 is released, so that, if there is a sufficient high inhalationsuction force in the inhalation channel of the powder inhaler, the flap20 can pivot or rotate from the horizontal first position into a secondposition that is pivoted downward relative to the horizontal firstposition. In the latter case, the movement of the flap 20 into itssecond position releases the portion 34 of the coupling member 30, whichenables the resilient member 40′, due to its compression, to move thecoupling member 30 slightly upward. By this rotational upward movementof the coupling member 30 the prolongation 33 extending from the lowerside of the coupling member 30 moves forward, thereby moving theprotective member 7 from its closed position to its open position andexposing the dosing recess 15 to the inside of the deagglomeratorarrangement (cyclone) of the powder inhaler, so that the dose of thepowdered medicament can be inhaled through the deagglomeratorarrangement and the inhalation channel as well as the mouthpiece.

Furthermore, as a result of this rotation of the flap 20 and thefollowing clockwise rotation of the coupling member 30 due to the actionof the resilient member 40′, in cooperation with that of the secondoptional resilient member mounted on the shaft-like portion of thecoupling member 30 at the opposite side with respect to the resilientmember 40′, the projection or cantilever 31 of the coupling member 30 isalso slightly moved clockwise along the inclination of a next drivetooth 16 of the units wheel 12 so as to bring the thickening 32 intoengagement with the respective drive tooth 16.

FIG. 1B shows a position of the inhalation actuated mechanism 18 afterinhalation has occurred.

After inhalation, when the user closes the cover of the powder inhaleragain, the metering member 5 is moved backward to the filling positionunderneath the medicament container of the powder inhaler, and thisbackward movement causes a counterclockwise rotation of the couplingmember 30 as the prolongation 33 thereof is moved backward with themetering member 15. The counterclockwise rotation of the coupling member30 is supported by the resilient member 40′ which is allowed to bedischarged and decompressed upon backward movement of the meteringmember 5. Due to this counterclockwise rotation of the coupling member30, the projection 31 is also rotated counterclockwise, thereby rotatingthe units wheel 12 counterclockwise by one step which decreases thedisplayed number of doses left in the container 4.

Since the coupling member 30 and the resilient member 40′ are moved backinto their initial positions, the end 41 of the resilient member 40′urges the flap 20 back into the horizontal position shown in FIG. 1A.Moreover, the coupling member 30 is then again held by the engagement ofits projection 34 with the flap 20, so that the whole powder inhaler hasthen been transferred into its initial position again.

FIG. 1C shows a perspective view of an alternative embodiment of theinhalation actuated mechanism 18 from a different side. In FIG. 1C, thesame components as those shown in FIGS. 1A and 1B are designated by thesame reference numerals, and as regards the functionality of thesecomponents, reference can be made to the above explanations. It shouldbe noted that, in the view of FIG. 1C, the units wheel 12 has beenomitted for clarity reasons.

In this alternative embodiment, for imparting to the coupling member 30a suitable force, which is released during inhalation, a secondresilient member 50, mounted on the shaft-like portion of the couplingmember 30, at the opposite side with respect to the resilient member40′, may be present. In particular, the second resilient member 50 maybe provided in the form of a drive spring which at one end 51 interactswith an adjacent lateral side surface of the coupling member 30 and atthe other end 52 rests on a surface positioned on a lateral portion ofthe chassis, close to a point wherein the shaft portion of the couplingmember 30 is hinged to. The downward movement of the flap 20 duringinhalation releases part of the force exerted by the second resilientmember 50 on the coupling member 30, while the closing of the cover ofthe powder inhaler tensions the second resilient member 50.

Although not shown in FIGS. 1A-1C and FIG. 2, similar to FIG. 4 and FIG.5 the flap 20 may be provided with a flag 22 which acts as a mark thatis visible through an opening in the mouthpiece 3 of the powder inhalerand indicates that a dose is ready for inhalation.

To confirm the advantages associated with the invention, a through lifebreath actuated mechanism activation flow rate (BAM-AFR)characterisation was performed. In particular, tests were carried on 66devices, not containing the powder formulation, being provided with abreath or inhalation actuated mechanism with the new flap according tothe invention and on corresponding 60 devices, not containing the powderformulation, being provided with a breath actuated mechanism with aprevious flap design according to the prior art.

The method was similar to that described in the European Pharmacopoeia8.0 for Inhalation Powders: Tests for Uniformity of Delivered Dose, andthe equipment for performing the tests comprised a device handling unitrig provided with a device seat, to fix the device during the experimentand the following units connected in the following order: the mouthpieceof the device was connected to a Dose Unit Sampling Apparatus for drypowder inhalers (DUSA—Copley Scientific) through a suitable adapter, aHEPA (High Efficiency Particulate Air) filter, a flowmeter (Copley), anda Critical Flow Controller (TPK model—Copley Scientific), in its turnconnected to a vacuum supply port. The DUSA was also connected to amanometer. Details on the working requirements of Copley instruments andapparatus (DUSA, flowmeter, Critical Flow Controller) known to theskilled in the art are also available in Copley Scientific Brochuresavailable at the company web site.

After initial leak check and having sealed any potential leaks atconnection points, the tests on the activation flow rate for each deviceand for the through life of each device were performed. Each device wasexposed to a starting flow rate of 20.0 l/min to confirm whether theflap was activated or not. If the flap was not activated, the device wasre-primed and retested at the flow rate increased by 2.5 l/min. If againthe flap was not activated, then the flow rate was increased a further2.5 l/min and retested. This continued until an activation of the flapwas recorded, up to a maximum flow rate of 60 l/min. The flow rate atwhich the activation occurs was recorded as its BAM-AFR. This method wasapplied to five doses at the start of life of the device (from the1^(st) to the 5^(th)), and ten doses at the end of life of the device(from the 111^(th) to the 120^(th)) with the intervening doses beingshot to waste at a higher flow rate.

The powder inhalers provided with the flap design according to theinvention resulted in a mean BAM-AFR of 25 l/min, while the powderinhalers with the previous flap design required a mean BAM-AFR of 38l/min. The results therefore showed a large reduction in the BAM-AFR forthe through life of the powder inhaler provided with the flap accordingto the present invention with respect to the powder inhaler providedwith the flap design according to the prior art. Moreover the new flapdesign allowed to achieve a variability of the activation flow rates forthe through life of the powder inhaler in the range of 20 to 32 l/min,which was very low with respect to the variability showed by theprevious flap design.

1-22. (canceled)
 23. A flap for an inhalation actuated mechanism of apowder inhaler, comprising: a base member comprising a plate-shaped flatportion; a skirt structure projecting upward from a surface of theplate-shaped flat portion of the base member; and a coupling portion tobe coupled to a resilient member of the inhalation actuated mechanism,wherein: the skirt structure comprises first side wall portions, whichsubstantially extend in a longitudinal direction of the base member, asecond side wall portion which extends between the first side wallportions in a width direction of the base member, and the couplingportion projects from a lower surface of the plate-shaped flat portionof the base member downward.
 24. The flap according to claim 23, whereinthe base member comprises a shaft portion at a rear end of the flatportion, the shaft portion being provided to pivotably support the flapin the inhalation actuated mechanism.
 25. The flap according to claim23, wherein a front end of the flat portion is at least partly rounded.26. The flap according to claim 23, wherein the flat portion has a firststraight longitudinal side and a second straight longitudinal side, thefirst and second longitudinal sides being connected by a combination ofa straight front end portion and a rounded front end portion.
 27. Theflap according to claim 26, wherein a length of the first longitudinalside is shorter than a length of the second longitudinal side.
 28. Theflap according to claim 23, wherein the second side wall portioncomprises an elongate thickening extending from the base member in amiddle portion of the second side wall portion.
 29. The flap accordingto claim 23, wherein the skirt structure comprises two of the first sidewall portions which are spaced from one another in the width directionof the base member and are wedge-shaped such that a height of the firstside wall portions gradually increases from a front end of the basemember towards a rear end of the base member.
 30. The flap according toclaim 23, wherein the second side wall portion is inclined towards arear end of the base member.
 31. The flap according to claim 23, whereinthe first side wall portions extend along the first and secondlongitudinal sides of the flat portion of the base member.
 32. The flapaccording to claim 31, wherein the first side wall portion, whichextends along the first longitudinal side of the flat portion of thebase member, is angled such that a part thereof extends substantiallyparallel to the straight front end portion of the base member.
 33. Theflap according to claim 23, wherein the coupling portion for theresilient member of the inhalation actuated mechanism extends from asurface of the base member downward which is opposite to the surfacefrom which the skirt structure projects upward.
 34. The flap accordingto claim 23, wherein the flap comprises a projection that projects froma shaft portion of the flap backwards; and wherein the projection isdesigned such that it acts as a counterweight upon a rotation of theflap in the inhalation actuated mechanism.
 35. The flap according toclaim 34, wherein the projection and the coupling portion are spaced ina width direction of the flap and extend substantially parallel to oneanother.
 36. A powder inhaler, comprising: a container for storing apowdered medicament; a metering member having a dosing recess to befilled with a dose of the powdered medicament from the container; amouthpiece being in communication with an inhalation channel forenabling inhalation of the dose of the powdered medicament contained inthe dosing recess of the metering member; and an inhalation actuatedmechanism which is coupled to a protective member for the dosing recessof the metering member such that, if the protective member is in aclosed position in which it at least partly covers the dosing recess,the inhalation actuated mechanism causes the protective member to moveto an open position, in which the protective member does not cover thedosing recess, if an inhalation suction force exerted by a user on theinhalation channel exceeds a predetermined value, wherein the inhalationactuated mechanism comprises the flap according to claim
 22. 37. Thepowder inhaler according to claim 36, wherein the flap is arranged suchthat it is pivotable between a first position and a second position,wherein the flap is coupled to the protective member such that, if thereis an inhalation suction force exceeding the predetermined value, theflap is moved from the first position to the second position, therebycausing the protective member to move from the closed position to theopen position.
 38. The powder inhaler according to claim 37, wherein theinhalation actuated mechanism comprises a resilient member which istensioned by a movement of the metering member from a filling position,in which the dosing recess is in alignment with an opening of thecontainer so as to be filled with the dose of the powdered medicament,to an inhalation position, in which the dosing recess is in alignmentwith the inhalation channel, wherein the resilient member is allowed todischarge upon a movement of the metering member from the inhalationposition to the filling position; wherein the resilient member isarranged such that it holds the flap in its first position if theresilient member is discharged, while the resilient member releases theflap if the resilient member is tensioned, so as to allow the flap to bemoved from its first position to its second position by the inhalationsuction force exceeding the predetermined value.
 39. The powder inhaleraccording to claim 38, wherein the inhalation actuated mechanismcomprises a coupling member coupling the flap to the protective memberwith the resilient member being coupled to the coupling member; andwherein the coupling member comprises a portion which is held by theflap when it is in its first position, while the portion of the couplingmember is released by a movement of the flap from its first position toits second position.
 40. The powder inhaler according to claim 39,wherein the resilient member is a spring attached to a shaft-likeportion of the coupling member.
 41. The powder inhaler according toclaim 39, wherein the inhalation actuated mechanism comprises a furtherresilient member which is mounted on a shaft-like portion of thecoupling member.
 42. The powder inhaler according to claim 41, whereinthe further resilient member is a spring mounted on the shaft-likeportion of the coupling member at an opposite side with respect to theresilient member.
 43. The powder inhaler according to claim 42, whereinthe further resilient member has a first end coupled to the couplingmember and a second end coupled to a chassis of the powder inhaler.